2 BULLETIN 119, U. S. DEPARTMENT OF AGRICULTURE. 



and by Benthani (1840, p. 139) in the subgenus Strophostyles. 

 Strophostyles Elliott is based on the American plant called PJiaseolus 

 umoellatus by Muhlenberg. American botanists generally consider 

 Strophostyles a valid genus, differing from Phaseolus in having the 

 keel curved but not spiral. The two keel petals are inflated near 

 the middle in the broadest part and each has a semicircular expansion 

 on the dorsal edge. The stigma is terminal; that is, there is no 

 appendage at the tip as in Phaseolus. The pods and seeds of Stroph- 

 ostyles are much like those of the mung and related species, and 

 it was apparently on these characters that Bentham associated the 

 two. The keel and stigma characters of Strophostyles, however, 

 indicate that there is no such close relationship. 



The five species possess the following characters in common: 

 Plants annual; stipules with a basal appendage; flowers yellow; 

 keel spirally coiled, bearing on one side a hornlike appendage; style 

 hairy, prolonged into a narrow appendage beyond the stigma; 

 stigma lateral, sub terminal; pods linear, sub terete, sometimes toru- 

 lose; seeds globose to oblong; hilum narrow, linear. The style 

 and stigma characters of the adsuki are like those of the kidney bean 

 (Phaseolus vulgaris) in that the terminal appendage is flattened, 

 while in the other four species it is terete. This difference is appar- 

 ently not significant, except as showing that these species truly belong 

 with Phaseolus. The other characters, however, seem sufficient to 

 warrant the recognition of a subgenus for the mung and its allies, 

 which may be called Ceratotropis, from the Greek words signifying 

 horn and Iceel. 



The mung bean is cultivated more or less extensively in all parts 

 of Asia where it will mature and also in southeast Africa, where it 

 was probably carried by Hindoo traders. The urd and the moth 

 bean are cultivated only in India. The adsuki is confined to Japan, 

 Manchuria, China, and Chosen (Korea), unless a similar bean in Nepal 

 and Sikkim is identical. The rice bean is most frequently seen in 

 China and India, but it is also cultivated in Japan and the Philippines. 



Presumably the cultivation of all of these was relatively more 

 important previous to the discovery of America, which led to the 

 general dissemination of the kidney bean and the Lima bean, both 

 of which are now largely cultivated in all the regions mentioned. 

 Nevertheless, the five oriental species are still of considerable agri- 

 cultural importance and doubtless will always be cultivated. All 

 of them have been rather extensively tested from the standpoint 

 of forage and of green-manure crops in the United States, especially 

 during the past six years, but it seems doubtful whether any of 

 them can compete in these respects with the cowpea and the soy 

 bean. As producers of seed for both human food and animal food, 

 however, there are possibilities in these crops well worthy of much 

 further investigation. Their final position in American agriculture 



